fuel pump rpm

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fuel pump rpm

Postby food111 » Mon Aug 17, 2015 2:01 pm


it is known that to check fuel pump by waveform analysis we must know pump rpm by waveform and some calculations and compared to specification, my question how to know rpm specification of any new pump the same model of that installed in the car ?

thank u
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Re: fuel pump rpm

Postby vasek » Thu Sep 10, 2015 12:51 am

On the waveform You can see the current consumed by the pump,the difference between the maximum and minimum current,number of lamellae on the rotor,the speed of rotation.For most pumps turbine type , the value
of the speed of rotation is about 4400 - 5200 at a voltage of 14.4 .The difference current is of about 1.3 amps .There is a dependence on the type of fuel, voltage at the pump , number of lamellae and manufacturer.If no fuel in tank or faulty fuel suction jet pump ,current can be reduced noticeably ,and the speed will increase to 7000 rpm and more.This is true for all simple pumps,not for pumps with control ECU and 3 phase brushless pumps .Here's an
example of operation of the feed pump AUDI Q7 3.0 TDI BUG:
fuel pump current.png
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Re: fuel pump rpm

Postby PicoPhil » Thu Sep 10, 2015 12:22 pm

James Dillon does an excellent book called Oscilloscope Diagnostics and this subject is covered on pages 85 to 93. Excellent read.Go to either Technical topics or Diagnostic assistance.
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Re: fuel pump rpm

Postby gbrodner » Thu Dec 24, 2015 9:49 am

is there anybody, who can explain me the particular periods of one cycle?
What is the reason for the alternating amperage and the clitches?
Thanks and greeting vom Munich
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